The purpose of this study is to examine the effects of subclinical malnutrition on the physical health and life expectancy in 300 elderly people over a five year period. The nutritional status of these elderly individuals (65 years and older) is evaluated by yearly clinical exams, a three day diet history, and biochemical analysis of blood samples for total protein, albumin, transferrin, iron, total iron binding capacity, vitamins A, C, D, E, B6, B12, folate, riboflavin, thiamine, cholesterol, HDL cholesterol, triglycerides, copper and zinc. The results of these individual assessments will then be used to determine whether poor nutritional status predisposes subjects to increased morbidity and mortality during the five year follow-up period. These elderly individuals are also being evaluated immunologically with skin tests and in vitro mitogen responses to detemine whether depressed immune function correlates with subclinical malnutrition in this population.